This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a career development project for Dr. Young. Larry J. Young is William P. Timmie Professor in the Department of Psychiatry and Behavioral Sciences, and Division Chief of the Behavioral Neuroscience Division at Yerkes. Throughout his career, Dr. Young has had a strong interest in the molecular and neural mechanisms underlying behavior. Dr. Young has continued to expand his area of research. He has initiated a collaboration with Dr. Mark Goodman to develop PET ligands for the oxytocin receptor. He has developed a method for developing transgenic voles. He has also collaborated with several colleagues and contributed to several important discoveries related to the neuroendocrinology and genetics of social behavior.